Valve manifolds are used for mixing different liquids. The valve manifold has a plurality of inflows through which different liquids or gases can be supplied, and one or more outflows through which the liquids or gases can be drained from the valve manifold. The inflows into the central mixing chamber and the outflows out of the central mixing chamber are controlled by diaphragm valves which can shut off the inflows into or the outflows from the central mixing chamber. EP 0 972 148 B1, for example, discloses a diaphragm valve which is adapted to individually shut or open two inflows to and two outflows from a central chamber, so that two inflows or outflows can be controlled by a common valve.
In order to remove residues of a liquid from the valve manifold, for instance if a different mixing ratio is needed or if a mixing with a previously used liquid is to be avoided, it has been necessary to rinse the entire valve manifold. The ports need to be removed, as a result of which any liquids remaining in the inflows will be lost. In addition, after cleaning and connecting the ports, it is required to fill the dead spaces in the ports again, resulting in a high consumption of the liquids.
It is therefore important to provide a valve manifold which allows a simpler and more efficient cleaning of the valve manifold.